Hydraulic valve operating mechanism



Aug.v 16, 1932. G. E. A. HALLETT 1,872,141

HYDRAULIC VALVE OPERATING MECHANISM Filed April 4. 1927 2 Sheets-Sheet l to 76 ig! 67 w QM kflmw G. E. A. HALLETT 1,872,141

HYDRAULIC VALVE OPERATING MECHANISM Filed April 4, 1927 2 Sheets-Sheet 2 Aug. 16, 1932.

gwuantoc (2 24/1 am I Patented Aug. 16, 1932 UNITED STATES PATIENT; OFFICE GEORGE E. A. HALLE'IT, or, DETROIT, MrjoriIeAN, Assrenon 'ro GENERAL MOTORS RESEARCH CORPORATION, OF DETROIT,'MICHIGAN, A CORPORATION OF DELAWARE HYDRAULIC VALVE OPERATING MECHANISM Application filed Apri14, 1927. Serial No. 180,915.

This invention relates to hydraulic mechanism for operating the valves of internal combustion engines and similar-devices, in

which a body of fluid is interposed between an operating part and an operated part'to transmit movement. In apparatus of this character one of the chief obstacles in the;

way of successful operation is thefact that air becomes mixed with the oilror other fluid,

forming an emulsion which it is very difficult to remove. According to this inventlon the oil supplied to replenish the fluid body to take care of losses from leakage and other causes is subjected to an operation inwhich air is effectively and positively removed prior to the admissionof the oil to the system. This is preferably accomplished by the employment of centrifugal action, as a result of which the air bubbles owing to their lighter weight collect in the center of the separator where provision is made for leading themitogether with some of the oil either tov the bearings or othersubjecting the piston to side thrusts as a result of cam action which would cause Wear;

in the guides, givingrise to leakage, I interpose a reciprocating-part between the cam;

shaft and the piston. This may be inthe form of a plunger suitably guided, and in 4D alinement with the piston. For convenience in manufacture the-guide for the plunger may.

be formed in the crank case and the plunger.

may be a relatively loose fit in the guide. The piston, on the contrary, must fit its guide very closely, and the latter is conveniently formed separately from the crank case and secured thereto in alinement with the first named supply oil to certain of the bearings through guide.

Oil is preferably fed to the system through ports formed in the piston and its guide,

these ports alining during portions of the stroke when the valve is not being actuated.

Other features of the invention will be disclosed in the following description.

In'thedrawings, Figure 1 is a diagrammatic view showing in partial vertical section an automobile engine to which my invention is shown applied. [Figure 2 is an enlarged detail view of portions of the structure shown in Figure 1.

Figure 3 is a section on line 33 of Figure 2. v

Figure 4; is a diagrammatic view, similar to Figure 1, showing my invention applied in a system of somewhat different type.

In Figures 1 and 2, I have illustrated an internal combustion engine of the Overhead valve type provided with the usual crank case 2, crank shaft 4, cylinders 6 and pistonsv 8. I have indicated at 10 one of the Overhead valves which is'held upon its seat by spring,

hardened steel andthe piston 28 is a close fit in the cylinder to prevent leakage of oil or other fluid which fills the chamber 20, conduit 22 and cylinder 26. Cylinder 26 is in alinement with bore 32 formed in the crank case and in whlch 1s fitted plunger 24 engaging the cam shaft-14. It will now be understood that with the system'filled with fluid, rotation of the cam shaft will cause plunger 24% and-piston 28 to move upwardlyin Opposition to spring 30 displacing the fluid in the system and causing plunger -16 to be forced downwardly opening the valve 10. o

. I have provided the following means to replenish the fluid in thesystem to insure effective operation: at 38 I have shown the usual engine driven oil pump Which may conduit 40, while conduit 41 leads to the usual dash pressure gage. Pump 38 likewise supplies oil through tube 42 to the combined separator and settling tank 44. Tube 42 may be provided with check valve 43 to prevent return of oil to the crankcase. It will be noted that the top of the tank is of conical form and tube 42 communicates tangentially with the tank just below the control portion as shown in Figure 3. Conduit 46 likewise extending tangentially from the tank leads oil from the bottom of the tank to passage 48 in cylinder 26. Piston 28 is provided with a peripheral groove 49 from which a plurality of passages 50 lead. to the interior of the piston. At the upper end of the piston is provided an upwardly opening check valve 51 yieldingly held upon its seat by spring 52. At the upper end of tank 44 is arranged a pressure relief valve 53 controlling the passage of oil from the tank into conduit 54 which may have a branch 56 leading to certain of the engine bearings or other parts re quiring lubrication. Conduit 54 discharges into crank case 2 and at some convenient point beyond the branch 56 is provided with a second pressure relief valve 58.

The operation of the system for replenishing the liquid column is as follows: A portion of the output of the pump 38 passes through conduit 42 to tank 44 in which it performs a whirling motion as a result of its tangential connection to the tank. This causes air bubbles to collect in the center of the tank while the heavier particles of oil seek the sides of the tank. When the pressure in the tank attains a certain value, valve 53 opens permitting oil to pass into conduit 54 from which a portion may pass to the bearings through branch 56. L V

The lower portion of tank 44 is" now filled with oil of the required density and from this portion of the tank oil passes through con duit 46 to port 48 in cylinder 26. During the non-operating portions of the stroke of the piston 28, groove 49 therein registers with port 48 and if the fluid body needs replenishing oil flows into the piston 28 and through check valve 51 into conduit 22.

Any suitable means, such as a permanent leak of small size or an'air vent valve such as shown in my prior application, Serial No. 126,297 filed July 31st, 1926, may if desired be mounted at the highest point in the chamber 20 to permit escape of air.

It will be apparent from the foregoing that I have provided effective means for removing air from the oil supplied the hydraulic system. The provision of the cylinder 26 and piston 28 separate from the crank case permits the use of materials having greater wear i""e sisting properties and, the parts being small, they are very easily machined. This arrangement likewise possesses the advantage that the piston 28 is relatively free of side thrust as it does not contact with the cam.

' Attention isalso called to the fact that the conduit 46 communicates with tank 44 slightly above the bottom thereof so that clogging of the conduit by collected sedimentis avoided. If desired, the tank may be provided with a suitable plug 57 in its bottom to permit periodic draining.

The form of hydraulic column shown in .Figures 1 and 2 is objectionable because of syphoning action. This objection does not apply to the construction illustrated in F igure ,4, which is an adaptation of my separator to hydraulic mechanism of the type disclosed and claimedin my prior application SerialiNo; 126,297 filed July 31st, 1926. In this device oil from the separator 44 is supplied to chamber 60 provided with pressure relief valve 62 communicating with chamber 64. During the non-operating strokes of the tappet 66 oil flows from the'reservoir 60 into valves, 2. body of fluid, said valve being pro vided with means in operative relation with said body of fluid, means operated by said engine for displacing said fluid to impart movement to said valve, means for replenish ing the fluid in' said body, and means for removing air from the fluid supplied to said body, said'la'st named means comprising an inertia separator.

2. In an engine having one of the usual valves, a body of fluid, said valve being provided with means in operative relation with said body of fluid, means operated by said engine for displacing said fluid to impart movement to said valve, means for replenishing the fluid in said body, and means for removing air from the fluid supplied to said body, said last named means comprising a conibined centrifugal separator and settling tan 3. In an engine having one of the usual valves, a body of fluid, said valve being provided with means in operative relation with said body of fluid, means operated by said en gine for displacing said fluid to impart movement to said valve, means for replenishing the fluid in said body, and means for removing air from the fluid supplied to said body, said last named means comprising a centrifugal separator, and means for conducting the air containing portions of said fluid away from said separator.

4. The combination of an engine having a circulating lubricating system, hydraulic valve actuating mechanism, means for supplying said hydraulic mechanism with oil from said system, and means for removing air from the oil supplied to said mechanism, and means for returning the air containing portions of said oil to the lubricating system.

5. The combination of an engine having a circulating lubricating system, hydraulic valve actuating mechanism, means for supplying said hydraulic mechanism with oil from said system, and means for removing air from the oil supplied to said mechanism, said last named means including a separating chamber provided with a pressure relief valve and a conduit for the return of the air containing portions of the oil to the system.

In testimony whereof I afiix my signature.

GEORGE E. A. HALLETT, 

